A Resource for the Protected Areas Database of the United States (PAD-US)

Data Sources & Processes


PAD-US is developed for regular publication through the process shown in the diagram below. The key components are State by State inventories, Federal agency collections, and other contributors, all integrated into the PAD-US data standard by USGS, and published in a variety of products and formats.


Federal Data

Federal data includes fee lands, easements, marine areas, designations, and proclamation boundaries.

This data is secured for publication in PAD-US via protocols defined by the Federal Lands Workgroup (FLWG), a subgroup of the National Boundaries Group under the Governmental Units Theme in the Federal Geographic Data Committee). The covers all Federal lands and waters deemed relevant to PAD-US. FLWG and the USGS PAD-US team have worked together to define specific processes for each agency’s data layers, as many have a number of relevant ownership, management, designation, and proclamation layers that are integrated into PAD-US.

The PAD-US Federal data is considered authoritative in PAD-US and replaces any Federal data maintained by individual State data-stewards. While there may be a few occasions when locally-collected Federal data is more accurate, Federal agencies at the national level are making great strides in having the most current and accurate information available.

Federal Fee Managers – Authoritative Data web services are available here. This layer includes fee simple parcels (where available) provided directly by managing agencies.  See the Federal Management Agencies web service if overlapping federal designations are desired.

Marine Feature Class

The Marine feature class generally contains two data sources – Marine Protected Areas by NOAA and Outer Continental Shelf lands managed by the Bureau of Ocean Energy Management.

The National Oceanic and Atmospheric Administration (NOAA) is the sole source of all Marine Protected Areas (MPAs) where PAD-US ‘Designation Type‘ = ‘MPA’ or where the ‘Aggregator Source‘ field references NOAA’s Marine Protected Areas Inventory (Example: “NOAA_MPAI_2017_PADUS.gdb/MPAI_2017_PADUS”).

PAD-US includes a subset of the NOAA Marine Protected Areas (MPAs) Inventory. Agencies nominate sites as MPAs, NOAA determines if they meet criteria for inclusion in the National System of MPAs. The NOAA MPA Inventory tracks everything: Nominated, Eligible, Ineligible and Member sites. Only Eligible and Member sites are submitted for PAD-US and the WDPA.

PAD-US describes everything submitted by NOAA as a “MPAs”, another designation type unique to the Marine feature class. The field ‘Local Designation‘ tracks the original designation, including many that overlap areas submitted by agencies for the ‘Fee’ feature class (e.g. National Parks, NWRs, State Parks, etc.). For more information about MPAs, find contact information for the NOAA MPAI Manager in the Stewards Database.

Outer Continental Shelf lands are held for their role in producing energy, mainly for oil drilling and exploration. These vast offshore areas are managed by the Bureau of Ocean Energy Management (BOEM) in the Department of the Interior. These lands can be found by searching for PAD-US “Des Tp = OCS”.

National NGO Data

Data from the following national non-governmental organizations are included in PAD-US:

The Nature Conservancy (TNC) maintains data on all of its holdings at the national level and contributes this information directly into PAD-US, overriding any locally-collected TNC data. TNC also contributes data to the National Conservation Easement Database (NCED), which is incorporated as-is into PAD-US as the ‘Easement’ feature class.

TNC also contributes data through its Secured Lands database, which seeks to track permanently protected areas in 18 Eastern States.

The Trust for Public Land contributes data through its Conservation Almanac program, which seeks to track all lands protected through public financing (bonds, taxes, etc.).

Ducks Unlimited contributes data from its Conservation and Recreation Lands database (CARL) which provides updates for select states in the upper Great Lakes region.

State and Local Data

State data collections in PAD-US are primarily Fee lands, with easements submitted separately by states into NCED which aggregates and contributes this data back to PAD-US. Few states have State designation or proclamation boundaries that could be included in PAD-US – but some states do have Marine Protected Areas which are often in the ‘Marine’ feature class. Many State data collections are now in PAD-US-consistent data structures, something strongly encouraged by USGS.

With 50 states, it is not currently possible for PAD-US to have updates for each State at every release, but USGS makes every effort to work with any updates available, particularly where they are in PAD-US format.

State data stewards also participate through the State Lands Workgroup as non-voting members of the National Boundaries Group.

Easement Data

Conservation and other open space easements are collected by the National Conservation Easement Database (NCED), a consortium of the Trust for Public Land, Ducks Unlimited, and other groups. NCED seeks to publish annual updates of easements held by Federal, State, and local agencies and by land trusts and other nonprofits.

NCED data is integrated directly into PAD-US and comprises the entirety of those lands held under easements in the U.S.

Integration details

The PAD-US team integrated individual source files into the PAD-US geodatabase from Federal, State, and nonprofit data-stewards by translating them into the PAD-US schema(unless already provided in the PAD-US format). The PAD-US team worked with data-stewards to create field maps/crosswalks to translate source data attributes into PAD-US attributes. Unless locally reviewed, conservation measures (‘GAP Status Code’, ‘IUCN Category’) and ‘Public Access’ were categorically assigned by ‘Designation Type’. Locally reviewed attributes from previous PAD-US version data  (‘GAP Status Codes’, ‘IUCN Categories’, ‘Public Access’, etc.) were also transferred over to PAD-US from previous PAD-US versions.

Expanding the database structure included the implementation of new feature classes (‘Designation’, ‘Proclamation’), to remove overlapping designations from fee ownership (‘Fee’ feature class). The PAD-US geodatabase was loaded with consideration for boundary size, type, and quality to ensure overlapping features are visible on maps and to support assessments of biodiversity or recreation.

The PAD-US team conducted multiple reviews of the fully integrated database utilizing Python scripts, as well as by summarizing the database with tables associated with each feature class. The Federal Lands Workgroup (FLWG) reviewed the federal update for PAD-US , as well as the PAD-US ‘Fee’ feature class that placed federal lands in context with State, local government and other fee owned protected areas. USGS approved the final geodatabase following a formal peer review process.

For more detailed information on the full integration process, please see the PAD-US metadata.

Users looking for PAD-US blank schema, translation scripts and crosswalks will find them on the ScienceBase page for PADUS.